loads of threads on this- do the lot (yes belts pulleys water pump variator and tensioner) for £450-500 at a good indie. Someone said main dealers were doing a discount at the moment too that might make them about the same.
I use an independent specialist in Newton Aycliffe called BMC. I'll be getting the belts, tensioners and variator replaced on my 156 there later this month. Call them on (01325) 300520 for a competitive quote.